*4.1. Materials*

Propolis was taken from an apiary around Shibin El-Kom City, Menoufia, Egypt, and kept frozen (−18 ◦C) until used. A total number of 40 samples of mackerel tuna fish (*Euthynnus affinis*) with an average weight of 100–150 g were obtained from a local aquacultural farm (Sadat City, Egypt). Mackerel tuna fish samples were transported to the laboratory in insulated boxes containing ice within one hour of fishing. All experiments were performed in April 2021 at the Department of Food Science and Technology, Faculty of Agriculture, Menofiya University, Shebin El-Kom City, Egypt.
